Heating Help

Help setting proper pressure for steam boiler.

I have a Honeywell L404A pressure control with settings you see on the photo below. I have cast iron baseboards all around two story house and all of them are hot while running at full steam. It seem like it gets pretty even heating, however there are some problems.
Specifically it’s water hummer, short-cycling. Also there is some water inside baseboards, since I can hear gurgles and sometimes water comes out from air valves. Heavy water hammering is mostly on the first floor of the house, the second floor just has some gargling.
I’ve read that high pressure can lead to hammering sounds as well condensate to stay up in the system.

What should I set the “MAIN” psi setting? Also what “DIFF” scale indicates and what should it be set to?

Thanks in advance.

RE

Oh boy, that's high!

Set the main at 1 psi. Set the differential at 1 psi. It's not printed, but go halfway between 0 and 2. You may have to fine tune it later on if it causes problems. You should never need to run above 2 psi on a residential boiler.

Main is the cut-out pressure. Differential is the number subtracted from the main, and sets the cut-in pressure.

RE 1

Thanks for your reply.
 
I just set 1 on MAIN and 1 for DIFF and now it seems to be on very short-cycling. Shuts down every 1 minutes, wait like 20-30 seconds then start up again.
 
How should I adjust it now?
 
Thank you

Hammering under pressure

Also check your main vents, as that pressuretrol may have been set high to squeeze the air out of the pipes.
You would benefit as well from having a good low pressure gauge (gaugestore.com 0-3psi. Only with that gauge can you know what pressure you have.--NBC

RE

Hi,
The pressure gauge not moving at all, it stays at the bottom of the cylindrical visible gauge. It's when I have my original setting that you can see on the attached photo.
Thanks

pressure gauge

i was refering to the pressure gauge which shows pressure on a round dial, not the pressure control, which controls the high and low settings.
next step with your system would be to check the main vents [usually on the pipes coming back to the boiler. my guess is that they are not allowing the air to escape easily, and therefore the boiler is doing their work.--nbc

How long does it take

for the boiler to start short-cycling? Do the radiators all heat fully before it short-cycles?

RE:How long does it take

Hi,

It's doesn't start short-cycling right away, it takes about 7 minutes to start doing that. Radiators aren't fully heated yet either. It seems like it is somewhere close to the middle of the process.

Thanks

RE:How long does it take

RE

Do you have any steam leaks? At the radiators, or in the piping? If the steam leaks out fast enough it may be dropping pressure very quickly. Is the boiler losing water during its cycle?

You can also try to raise the main PSI setting to a point where it settles out. But the lower the better.

RE

No, there are no leaks at all and it doesn't loos water either.

Here is a little info about my setup. I have 170K BTU Burnham boiler. My leaving room is about 400 sf and there are two 5ft long baseboards and one 3ft one. On the second floor there are 3 bedrooms. Two bedrooms have 5ft long and one room has 3ft one.

Can it be that my boiler is too big, and it's ability to produce steam exceeds the system's ability to condense steam?

Thanks

Do you have any other radiators?

or baseboard. What you list is about 22kbtu's of heat and your boiler is 170Kbtu's. That's some way over sized boiler. Does the house heat up?

RE: Do you have any other radiators?

>Do you have any other radiators?
No, just those are listed.

>Does the house heat up?
Now, when outside temp is about 35F, it can make to 70 relatively easy, but at Jan, Feb it almost impossible get to 70F.

I wonder if the high pressure

is due to the lack of radiative surface area, so they cranked the pressure to try and get more btu's from each square foot. The vents are most likely rated no more than 3 pounds of pressure.